1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Alecsey [184]
3 years ago
15

Suppose you left your lawn mower out all winter, and it is very rusty. Of your 250,000J of work, only 100,000J go towards cuttin

g the lawn. What is the efficiency of the lawn mower now?
A 40%
B 0.4%
C 0.04%
D 4%

REMINDER: PLEASE SHOW YOUR WORK!!!
Physics
1 answer:
mihalych1998 [28]3 years ago
7 0
Efficiency  = 

                 (useful work you get out of it) / (work you put into it)

           =        (100,000 J)  /  (250,000 J) 

           =            0.4  =  40%    (choice-A)


You might be interested in
0. 85 kg of lead, specific heat 128 J/kgC, is heated from 50 C to 95 C. How much heat energy did the sample absorb?
Zanzabum
4896

0.85 x 45 x 128 = 4896

Change in energy = specific heat capacity x mass x change in temperature
5 0
2 years ago
An object falls from the top of a building that is 25 m high. Air resistance is negligible.
Vlada [557]

The velocity of the object s calculated as 22.1 m/s.

<h3>What is the speed of the object?</h3>

Given that we can write that;

v^2 = u^2 + 2gh

Now u = 0 m/s because the object was dropped from a height

v^2 = 2gh

v = √2 * 9.8 * 25

v = 22.1 m/s

Learn more about velocity:brainly.com/question/18084516

#SPJ1

5 0
2 years ago
Help please ASAP !!!
mezya [45]
What’s the weight and how high is the clif
7 0
3 years ago
A car has a mass of 1,000 kilograms. The weight of the car is blank newtons. Use g = 9.8 N/kg for gravity.
Komok [63]
The weight of an object is mass*acceleration. In this case mass*g.
1000*9.8=9800
So the car has a weight of 9800 N.
3 0
3 years ago
The width of the central maximum is defined as the distance between the two minima closest to the center of the diffraction patt
Gnom [1K]

Answer:

The value of the angle is \bf{ \sin^{-1}[h/am_{e}v]}.

Explanation:

Given:

The condition for diffraction minima is

a \sin \theta = m \lambda~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(1)

where, a is the slit-width, \theta is the angle of incidence, m is the order number and \lambda is the wavelength of the light.

The wavelength of an electron traveling through a medium is governed by de Broglie's hypothesis.

According to de Broglie's hypothesis

\lambda &=& \dfrac{h}{p}\\               &=& \dfrac{h}{m_{e}v}

Here, h is Planck's constant, m_{e} is the mass of the electron and v is the velocity of the electron.

For first minimum m = 1.

From equation (1), we have

&& a \sin \theta = \dfrac{h}{m_{e}v}\\&or,& \theta = \sin^{-1}[\dfrac{h}{am_{e}v}]

6 0
3 years ago
Other questions:
  • How many neutrons does element X have if its atomic number is 23 and its mass number is 90?
    15·2 answers
  • Water cools from2oC to -2oC. During this time, what happens to the motion of the molecules? A) The motion of the molecules stops
    5·1 answer
  • When we kept the Earth's mass the same, but shrank its size, we saw that had an effect on its escape speed. Albert Einstein used
    8·1 answer
  • On a timer !
    6·2 answers
  • CIAMELCH<br> Rearrange spelling
    13·1 answer
  • The earliest known records describing electric charge involve the use of _____.
    8·2 answers
  • Is the text in red correct (0n0')
    6·1 answer
  • 14. If 100 grams of sodium nitrate are dissolved in 100 grams of water
    5·1 answer
  • What property of sound does a decibel measure
    13·2 answers
  • When the car was stopped by the tree, its change in velocity during the collision was -6 meters/second. This change in velocity
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!